Memory sticks: Can I expand my short-term memory?

Never mind mastering a second language or a subject syllabus, most us have enough difficulty remembering the orders for a round of drinks at the pub. That’s because the average short-term, working memory can only hold five to seven pieces of information at any one time. This limit constrains pretty much everything you want to do with your brain, so wouldn’t it be great if you could overcome it?

Unfortunately, past attempts by cognitive scientists to increase people’s working memories have largely failed. Although subjects trained in specific strategies, such as rehearsing long strings of numbers, often improved their performance on the particular task at hand, they were no better at other problems. As a result, researchers are now testing the effect of more variable and demanding tasks. For example, Jason Chein at Temple University in Philadelphia, Pennsylvania, uses software that asks people to answer questions about a string of successive sentences while simultaneously remembering the last word of each sentence. It is very difficult to develop conscious shortcuts to deal with the two conflicting sources of information, so the brain is forced to make more long-lasting changes. The idea is that these will then enable you to perform better on other types of memory tasks.

The new techniques work a treat, typically increasing memory span by around 15 per cent over a training course of five weeks. In practice that could mean expanding your working memory from seven to eight items. What this means for intelligence, though, is hotly contested. Some researchers doubt that a better working memory will help in other areas of cognition. But others point out that working memory underpins a whole swathe of cognitive abilities from logical reasoning and arithmetic to verbal skills and reading comprehension. What’s more, numerous studies show these mental skills improve following working memory training (Psychonomic Bulletin & Review, vol 18, p 46).